Open this photo in gallery: Britain's Prime Minister Rishi Sunak visits Harlow Police Station during a media visit in Essex on Feb. 16.DAN KITWOOD/Getty Images Beleaguered British Prime Minister Rishi Sunak on Friday urged voters, and his restless party, to stick with him after two English districts elected opposition-party lawmakers in seats that Sunak’s Conservatives had held for years. The results will worsen fears among Conservatives that, after 14 years in power, the party is heading for a drubbing when a national election is held in less than a year. The Tories consistently lag between 10 and 20 points behind...